MAJOR PROJECT REPORT ON TESLA TURBINE

SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS

1 CHAPTER 1 INTRODUCTION The objective of the project is to study the constructional features of a TESLA TURBINE and making it feasible for economical and consistent use. Nikola Tesla invented the bladeless turbine in 1913. This turbine is a radial turbine. A Radial turbine is a turbine in which the flow of the working fluid is radial to the shaft (i.e., 90degrees). The Tesla turbine is also known as the boundary layer turbine, cohesion-type turbine, and Prandtl layer turbine in general. The Tesla turbine is a bladeless centripetal flow turbine. It is referred to as a bladeless turbine because it uses the boundary layer effect and not a fluid impinging upon the blades as in a conventional turbine. The Tesla turbine is also known as the boundary layer turbine, cohesion-type turbine. Bioengineering researchers have referred to it as a multiple disk centrifugal pump. One of Teslas desires for implementation of this turbine was for geothermal power. Tesla Turbine, though proposed by the famous Croatian engineer Nikola Tesla years ago, is still to find its foot among the modern power turbines. Analysts are divided as to what exactly is the main reason behind the Tesla Turbine not taking off as well as it should have, given its unique factors. There are many reasons for this, but the general agreement is that the low torque produced by its rotor is probably its biggest drawback. After a thorough investigation about the various factors plaguing the working of the Tesla Turbine, the need to change the working fluid from the current air / water at room temperature became very evident. Since all the fluids used till now have yielded a very low torque, it became very clear that a new fluid, which facilitates high momentum transfer from the fluid to the rotor, was the need of the hour. Thus, this study investigates the use of a new working fluid and also analyzes its effects, structural and thermal, on the rotor. The structural and thermal effects analysis indicates that the current Tesla Turbine rotor materials will fail to prevent the rotor from excessive stress concentration and corrosion. Thus, with the proposal of a new working fluid came the imperative of proposing a new material for Tesla Turbine rotors, which will complement the new working fluid. As a result, this study proposes two new aspects for a Tesla Turbine: a new working fluid and a new rotor material. It is expected that once these proposals are implemented, the improved torque Figure1.1 - Tesla Turbine MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 2 generation by the Tesla Turbine will improve its acceptance levels and lead to its increased popularity. Moreover talking about the structural analysis of the tesla turbine structural analysis of the rotor components (turbine blades) have so far been mostly confined to conventional turbines like steam turbines, gas turbines and wind turbines. These studies dealt with the structural and dynamic stresses, the crack propagation etc. experienced in actual working conditions by the turbine blades. Though analyses of more specialized turbines like aero-engine turbines have been done, Tesla Turbine analysis papers remain highly elusive. Very few papers have been written researching Tesla Turbine because of its low level of commercial adoption. This was designed, tested and analyzed a multiple-disk Tesla type fan two-dimensionally using the conservation of angular momentum principle. Their study showed that Tesla Turbines exhibited exceptionally low performance characteristics, due to the low viscosity, tangential nature of the flow, and large mechanical energy losses at both suction and discharge sections that are comparable to the total input power. Their research determined the local and shearing stresses developed within the rotor as also the power transmitted from the air to the rotor . From this study, the main reason for low torque, low viscosity of the working fluid, was identified and this principle played a significant role in the proposal of the new working fluid later on in this study. After discussing the relative motion of rotating surfaces, the transport equations describing the flow between parallel rotating disks are derived, estimating the boundary layer thickness under laminar and turbulent regimes, leading to expressions yielding the width between consecutive disks. They have also described the device behavior acting as an air compressor or water pump. Even they have stated in their paper that a comprehensive discussion of the fluid mechanics involved in the design of Tesla Turbine components has never taken place. From their analysis, it became clear that virtually no consideration was ever given for exploring new materials for the construction of Tesla Turbine rotors. This huge void had to be filled, but by doing so, the close relation between the working fluid and the rotor material had to be taken into account. Armstrong made a modified Tesla Turbine and analyzed it way back in 1952. But in those days, the science of composite materials was not advanced enough for him to explore the use of laminated composite materials as rotor materials. But this study does exactly that i.e. proposing the new rotor material but within the framework of the laminar fluid characteristics of the new working fluid proposed.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 3 1.1 History A Tesla turbine is a quite unique technology. It was invented and patented by Nikola Tesla on the 21st October 1909 at the United States Patent Office from experiments done in England. The US patent 1061206 was granted on the 6th May 1913, although historical documents suggest that that Tesla first showed a 200 horsepower (about 150kw) 16,000 RPM version on the 10th of July 1906 (on Teslas 50th birthday).

From what Tesla wrote in the patent it seems his experiments were mainly done with fluids but had confirmed it works with air as well. Tesla had his own personal requirements for a generator for his laboratory. You have to remember use of electrical power was still in its infancy which Tesla played a critical role developing many of the electrical components we now take for granted. Typically Tesla found his alternative and better way of generating power, using a steam boiler powering a tesla turbine which in turn powered an AC generator.

Unlike conventional turbines, jet engines and most pumps, Teslas turbine can be designed to be reversible with no loss in efficiency. Normally compressed air, fluids or steam is applied to the inlet and the turbine spins giving a mechanic rotational output. However, it can also double up as a pump, by rotating the shaft the air/fluid/steam can and be sucked and blown from the inlets / outlets. This makes it unique in being a reversible turbine and a reversible pump. However efficiency increases can be made by tailoring the pump to the medium. In other words an air powered turbine may have some slight design changes compared to water powered turbine.

Sadly unlike the work done with electricity the Tesla turbine never became popular and was simply forgotten about. Only in the last few years has there been new interest. Tesla turbines are also known as cohesion turbines, bladeless turbines, boundary layer turbines and Prandtl layer turbines. Interestingly, using the word "turbine" to describe Tesla's invention seems a bit misleading. That's because most people think of a turbine as a shaft with blades -- like fan blades -- attached to it. In fact, Webster's dictionary defines a turbine as an engine turned by the force of gas or water on fan blades. But the Tesla turbine doesn't have any blades. It has a series of closely packed parallel disks attached to a shaft and arranged within a sealed chamber. When a fluid is allowed to enter the chamber and pass between the disks, the disks turn, which in turn rotates the shaft. This rotary motion can be used in a variety of ways, from powering pumps, blowers and compressors to running cars and airplanes. In fact, Tesla claimed that the turbine was the most efficient and the most simply designed rotary engine ever designed.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 4 CHAPTER 2 CONSTRUCTION The project mainly concentrates on use of muscular force to compress air which is used as the working fluid in the turbine. Construction of the project can be categorised in three parts as following: 1. Turbine 2. Air Compression Unit 3. Storage Unit 4. Power Generation Unit The above mentioned parts are discussed in detail in the following sections. 2.1 TESLA TURBINE A Tesla turbine consists of a group of smooth disks held together with spacers in between them, with nozzles applying a moving fluid tangentially to the disk. The fluid rotates the disk due to viscosity of the fluid and the adhesion of the surface layer of the fluid to the disc. Since there are no projections in the rotor, it is very sturdy. All the plates and washers are interference-fitted on to a shaft provided with bearings at both ends. This construction allows free expansion and contraction of each plate under the constantly changing combined effect of heat and centrifugal force. The other advantages of such an arrangement are higher resultant active plate area and thus more power, higher efficiency, reduced warping, diminished leakage and reduced friction losses. The rotor is better suited for dynamic balancing and since surface friction resists disturbing forces, a quiet running is ensured. Because of this and also because of the flexibility of the discs, the turbine is insulated from damages which are usually caused by vibration or turbulence. 2.1.1 Working Principle When a fluid flows around the outside of a body, it produces a force that tends to drag the body in the direction of the flow. The drag acting on a moving object such as a ship or an airplane must be overcome by the propulsion system. Drag takes two forms, skin friction drag and form drag. Skin friction drag is due to the viscous shearing that takes place between the surface and the layer of fluid immediately above it. This occurs on surfaces of objects that are long in the direction of flow compared to then height. Such bodies are called streamlined. When a fluid flows over a solid surface, the layer next to the surface may become attached to it (it wets the surface). This is called the 'no slip condition'. The layers of fluid above the surface are moving so there must be shearing taking place between the layers of the fluid. The shear stress acting between the wall and the first moving layer next to it is called the wall shear stress and denoted w. MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 5 The result is that the velocity of the fluid u increases with height y. The boundary layer thickness is taken as the distance required for the velocity to reach 99% of UO. This layer is called the boundary layer and is the boundary layer thickness. Fig. 2.1 Shows how the velocity "u" varies with height "y" for a typical boundary layer. In a pipe, this is the only form of drag and it results in a pressure and energy lost along the length. A thin flat plate is an example of a streamlined object. Consider a stream of fluid flowing with a uniform velocity UO. When the stream is interrupted by the plate (Fig. 2.2), the boundary layer forms on both sides. The diagram shows what happens on one side only. Figure 2.2- Boundary Layer The boundary layer thickness grows with distance from the leading edge. At some distance from the leading edge, it reaches a constant thickness. It is then called a fully developed boundary layer. The Reynolds number for these cases is defined as:

x is the distance from the leading edge. At low Reynolds numbers, the boundary layer may be laminar throughout the entire thickness. At higher Reynolds numbers, it is turbulent. This means that at some distance from the leading edge the flow within the boundary layer becomes turbulent. A turbulent boundary layer is very unsteady and the streamlines do not remain parallel. The boundary layer shape represents an average of the velocity at any height. There is a region between the laminar and turbulent section where transition takes place The turbulent boundary layer exists on top of a thin laminar layer called the laminar sub layer. The velocity gradient within this layer is linear as shown. A deeper analysis would reveal that for long surfaces, the boundary layer is turbulent over most of the Figure 2.1- Boundary Layer ThicknessMAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 6 length. Many equations have been developed to describe the shape of the laminar and turbulent boundary layers and these may be used to estimate the skin friction drag. Note that for this ideal example, it is assumed that the velocity is the undisturbed velocity Uo everywhere outside the boundary layer and that there is no acceleration and hence no change in the static pressure acting on the surface. There is hence no drag force due to pressure changes. Calculating Skin Drag The skin drag is due to the wall shear stress w and this acts on the surface area (wetted area). The drag force is hence: R = w x wetted area. The dynamic pressure is the pressure resulting from the conversion of the kinetic energy of the stream into pressure and is defined by the expression

. The drag coefficient is defined as

Note that this is the same definition for the pipe friction coefficient Cf and it is in fact the same thing. It is used in the Darcy formula to calculate the pressure lost in pipes due to friction. For a smooth surface, it can be shown that CDf = 0.074(Re)x-1/5

(Re)x is the Reynolds number based on the length. (Re)x =

On a small area the drag is dR = w dA. If the body is not a thin plate and has an area inclined at an angle to the flow direction, the drag force in the direction of flow is

w dA cos.

Figure 2.3 Force Diagram The drag force acting on the entire surface area is found by integrating over the entire area. R =

F cos Drag F MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 7 2.1.2 Construction Compared to a reciprocating engine, the Tesla turbine is simplicity incarnate. The two most important parts of the turbine, the rotor and the stator, are explained ahead in more detail. Rotor Unlike the conventional turbine, the Tesla turbine does not have blades and uses a combination of disks and spacers instead. The diameter and number of the disks can change depending upon factors concerned with a particular application. Each disk is provided with openings surrounding the shaft. Between every two discs, there are metal spacers provided to ensure a gap is maintained between discs, so as to ensure free flow of fluid. Once a free flow is ensured, space should be provided for the fluid to exit, and for that, the above mentioned openings are provided. All the discs and spacers are interference-fitted on the shaft and thus their rotation is transferred to the shaft. The rotor of the turbine is designed using compact disks and shaft in the center. The detailed drawing of the designed rotor is provided below.

Stator The rotor assembly is enclosed within a square stator, which is the stationary part of the Tesla turbine. The square shape should be just slightly bigger than the rotor in order to allow efficient flow of fluid. The stator also has an inlet in the form of a hole. This is the fundamental design. To rotate the turbine, a high-pressure fluid is passed through the hole provided at the top. The fluid makes its way through the rotor disks and causes the rotor to rotate. Finally, the fluid exits from the exhaust ports at the center of the turbine. The stator of the turbine consists of the following parts: a. End Plates The plates of the turbine are the covering at the two ends of the casing. These plates are made of acrylic sheet. A detailed drawing of the end plates is provided below. i. Inner End Plates

Figure 2.7 Outer Plate B MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 10 b. Casing The casing of turbine is cylindrical in shape and is made up of PVC. The rotor of the turbine rotates in this cylindrical casing which is of slightly larger diameter then the disks of the rotor. There is a hole provided at the top of the casing which is for the inlet of the air through the nozzle. The detailed drawing showing the casing of the turbine in shown below.

Figure 2.8 Turbine Casing

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 11 c. Nozzle Assembly The air is injected through the nozzle in the turbine. The nozzle assembly consists of the main nozzle and the nozzle casing. This is by far the most important element in achieving and fine tuning the efficiency of the disk turbine. A properly designed nozzle has a complex shape that determines the efficiency of converting gas pressure to shaft horsepower. The nozzle of the turbine is simple in construction, cylindrical in shape and is fabricated using lathe. The details of the nozzle and the nozzle casing are shown in the drawing below.

Figure 2.9 Nozzle

Figure 2.10 Nozzle Casing

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 12 2.2 AIR COMPRESSION UNIT The air compression unit consists of the exercising machine which is used as the compressor for the system. The air is compressed by the muscular force applied on the exercising machine by the user. This compressed air is transferred to the storage cylinder via non-return valves. The compression unit comprises of the following parts: a. Foot Air Pump b. Pneumatic Non-return Valves 2.2.1 Foot Air Pump An air pump is a device for pushing air. Examples include a bicycle pump that are used to aerate an aquarium or a pond via an air stone a gas compressor used to power a pneumatic tool, air horn or pipe organ, a bellows used to encourage a fire; a vacuum cleaner and a vacuum pump. These pumps are often not specifically designed for bicycle use. They do not generate very high pressures so do not work well for narrow road-bike tires, but are fine for large low-pressure tires as found on mountain bikes. The pump which we are using here is a foot pump, containing a heavy duty cylinder of diameter 8cm working pressure is 0-100 Psi or 0-7 bar pressure. The pressure gauge has been removed from it for our convenience and the proper transference of pressurized air with the help of hose pipe. 2.2.2 Pneumatic Non-return Valve It is commonly called as ANRV of 15 mm diameter having a pressure resistance of 10 kg/cm.It is also made of plastic material so that air leakage is minimum or negligible. Pneumatic non-return valves are used where a normal non-return valve would be ineffective. This is for example where there is a risk of flood water entering a site but an equal risk of pollution or a chemical spills leaving a site and polluting the environment. Pneumatic non-return valves are installed below ground and can be used to pneumatically lock the non-return valve closed thus containing a site in the event of a spill. It is common practice to lock sites using pneumatic non-return valves during the loading or transferring of chemicals or hazardous waste. Pneumatic non-return valves have a longer service life when compared to pneumatic bladder systems.

Figure 2.11 ANRV MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 13 2.3 STORAGE UNIT The air compressed using the pumps is stored in a cylinder. A pressure gauge is mounted on the cylinder for measuring the pressure inside the cylinder. The stored air transferred to turbine for the required purpose. The flow of air to the turbine is controlled by a gate valve. The storage unit consists of the following parts: a. Cylinder b. Pressure Gauge c. Gate Valve 2.3.1 Cylinder Now to store the pressurized air, we have used a cylinder of suitable capacity so that air at pressure can enter the cylinder and then pressurized air from cylinder is passed to the turbine.

Figure 2.12 Cylinder 2.3.2 Pressure Gauge It is used for measuring the pressure of air inside the cylinder. A pressure gauge is a common component in operations from various industries across the world. But not every gauge is created equally or made for every situation. WIKA Instrument Corporation has been on the forefront of innovation and quality for pressure gauges and pressure instruments for over 60 years, making us the pressure gauge expert for diverse industries and applications. Gauges with bourdon tubes are the most common pressure measuring devices used today. They combine a high grade of measuring MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 14 technology, simple operation, ruggedness and flexibility with the advantages of industrial and cost-effective production. Needing no external power supply, bourdon tube gauges are the best choice for most applications. Pressure gauges are crucial components of most processing systems. In these environments, a pressure gauge needs to be reliable, accurate and easy to read to help prevent failure in everyday operations. Therefore, how a gauge is constructed and tested is extremely important for reliability, safety and peace-of-mind. After all, failures can cost time, money and productivity loss. 2.3.3 Gate Valve We have used a plastic gate valve having inner diameter of 15mm. According to functioning of a simple gate, same is the principle behind the working of the gate valve. It is used to transmit the pressurized air from one hose pipe to other. In this, there is no chance of leakage if the connection is made by Teflon tape. The gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restriction is desired. The gate faces can form a wedge shape or they can be parallel. Gate valves are primarily used to permit or prevent the flow of liquids, but typical gate valves shouldn't be used for regulating flow, unless they are specifically designed for that purpose. Because of their ability to cut through liquids, gate valves are often used in the petroleum industry. For extremely thick fluids, a specialty valve often known as a knife valve is used to cut through the liquid. On opening the gate valve, the flow path is enlarged in a highly nonlinear manner with respect to percent of opening. This means that flow rate does not change evenly with stem travel. Also, a partially open gate disk tends to vibrate from the fluid flow. Most of the flow change occurs near shutoff with a relatively high fluid velocity causing disk and seat wear and eventual leakage if used to regulate flow. Typical gate valves are designed to be fully opened or closed. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low frictional loss. Gate valves are having either a rising or a non-rising stem. Rising stems provide a visual indication of valve position because the stem is attached to the gate such that the gate and stem rise and lower together as the valve is operated. .

Figure 2.13 Gate Valve MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 15 2.4 POWER GENERATION UNIT The power generated by the turbine is transferred to an electricity generator using a pair of spur gear. The electricity then generated is can be used for the required purposes. For the purpose here we have used it for lighting the LEDs. The following parts are covered in this unit: a. Dynamo b. Spur Gear c. LED(Light Emitting Diode)

2.4.1 Dynamo A dynamo is an electrical generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter. Today, the simpler alternator dominates large scale power generation, for efficiency, reliability and cost reasons. A dynamo has the disadvantages of a mechanical commutator. Also converting alternating to direct current using power rectification devices (vacuum tube or more recently solid state) is effective and usually economic. The word dynamo (from the Greek word dynamis; meaning power) was originally another name for an electrical generator, and still has some regional usage as a replacement for the word generator. A small electrical generator built into the hub of a bicycle wheel to power lights is called a hub dynamo. The dynamo uses rotating coils of wire and magnetic fields to convert mechanical rotation into a pulsing direct electric current through Faraday's law of induction. A dynamo machine consists of a stationary structure, called the stator which provides a constant magnetic field and a set of rotating windings called the armature which turn within that field. The motion of the wire within the magnetic field causes the field to push on the electrons in the metal, creating an electric current in the wire. On small machines the constant magnetic field may be provided by one or more permanent magnets larger machines have the constant magnetic field provided one or more electromagnets which are usually called field coils. The commutator was needed to produce direct current. When a loop of wire rotates in a magnetic field, the potential induced in it reverses with each half turn, generating an alternating current. However, in the early days of electric experimentation, alternating current generally had no known use. The few uses for electricity, such as electroplating, used direct current provided by messy liquid batteries. Dynamos were invented as a replacement for batteries. The commutator is essentially a rotary switch. It consists of a set of contacts mounted on the machine's shaft, combined with graphite-block stationary contacts, called "brushes", because the earliest such fixed contacts were metal brushes. The commutator reverses the connection of the windings to the external circuit when the potential reverses, so instead of alternating current, a pulsing direct current is produced.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 16 2.4.2 Spur Gear A gear is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine. Geared devices can change the speed, torque, and direction of a power source. The most common situation is for a gear to mesh with another gear however a gear can also mesh with a non-rotating toothed part, called a rack, thereby producing translation instead of rotation. The gears in a transmission are analogous to the wheels in a pulley. An advantage of gears is that the teeth of a gear prevent slipping. When two gears of unequal number of teeth are combined a mechanical advantage is produced, with both the rotational speeds and the torques of the two gears differing in a simple relationship. In transmissions which offer multiple gear ratios, such as bicycles and cars, the term gear, as in first gear, refers to a gear ratio rather than an actual physical gear. The term is used to describe similar devices even when gear ratio is continuous rather than discrete, or when the device does not actually contain any gears, as in a continuously variable transmission. We have used the spur gears or straight-cut gears are the simplest type of gear. They consist of a cylinder or disk with the teeth projecting radially, and although they are not straight-sided in form, the edge of each tooth is straight and aligned parallel to the axis of rotation. These gears can be meshed together correctly only if they are fitted to parallel shafts. These when connected to the shaft of the turbine, transfer the motion from one form to other. Its diameter was 6mm so one end of the shaft has been given the radius of 6mm. as a result the inner side of the gear is fixed in the shaft of the turbine. Gear terminologies are as follow in the diagram drawn below:-

Figure 2.14 Spur Gear MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 17 2.4.3 LED (Light Emitting Diode) A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in many devices and are increasingly used for other lighting. Appearing as practical electronic components in 1962,

early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet, and infrared wavelengths, with very high brightness. When a light-emitting diode is forward-biased (switched on), electrons are able to recombine with electron holes within the device, releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. An LED is often small in area (less than 1 mm2), and integrated optical components may be used to shape its radiation pattern.

LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. LEDs powerful enough for room lighting are relatively expensive and require more precise current and heat management than compact fluorescent lamp sources of comparable output. Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting, advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and sensors to be developed, while their high switching rates are also useful in advanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances. Now LED is being lit by the rotational motion of the dynamo which is caused by the working of the gear motor that is fitted inside the dynamo which is connected to the main shaft of turbine. The motion from one shaft is passed to another by the means of gear and thus effective lightening of LED is done and hence the main motive of project is done that is the conversion of the one kind of energy to the other form by the means of the bladeless turbine.

Figure 2.15 Light Emitting Diode MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 18 CHAPTER 3 MATERIALS USED Several kinds of materials are used for the fabrication of the project. The material used for the fabrication purpose is carefully selected so that the required purpose is fulfilled in the best economical way. Different materials used in the fabrication of the project are discussed below. 3.1 ACRYLIC SHEET Known by trade names such as Plexiglass, Acrylite, and Lucite, this material is great for glazing, windows, cutting boards, or anywhere a clear material is needed. It has better optical clarity than glass. It is light in weight and has good impact strength and moreover it has clear surface.

Figure 3.1 Acrylic Sheet 3.2 PVC PIPE Polyvinyl chloride PIPE, commonly abbreviated PVC, is the third-most widely produced plastic, after polythene and epolypropylene. PVC is used in construction because it is more effective than traditional materials such as copper, iron or wood in pipe and profile applications. It can be made softer and more flexible by the addition of plasticizer. In this form, it is Figure 3.2 PVC Pipe MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 19 also used in clothing and upholstery, inflatable products and many applications in which it replaces rubber. 3.3 COMPACT DISK CD stands for "Compact Disc." CDs are circular discs that are 4.75 in (12 cm) in diameter. The CD standard was proposed by Sony and Philips in 1980 and the technology was introduced to the U.S. market in 1983. CDs can hold up to 700 MB of data or 80 minutes of audio. The data on a CD is stored as small notches on the disc and is read by a laser from an optical drive. The drives translate the notches (which represent 1's and 0's) into usable data. The first CDs were audio CDs, which eventually replaced audio tapes (which earlier replaced records). Audio CDs have the advantage of allowing the user to jump to different places on the disc. CDs can also be listened to an unlimited number of times without losing quality. Audio tapes can start to lose quality after listening to them as few as ten times. This is because the laser that reads the data on a CD doesn't put pressure on the disc, whereas the play heads on a tape deck slowly wear away the magnetic strip on the tape. In 1985, CD-ROMs hit the computer market. Because they could store far more information than floppy discs (700 MB compared to 1.4 MB), CDs soon became the most common software format. In 1988, the CD-R (CD-Recordable) technology was introduced, allowing computer users to burn their own CDs.

Figure 3.3 Compact Disks

3.4 BALL BEARINGS A ball bearing is a type of rolling element bearing that uses balls to maintain the separations between the bearing races. The purpose is to reduce rotational friction and support radial and axial loads.it achieves this by using at least two races to contain the walls and transmit the loads through the wall in most applications, one race is stationary and the other is attached to the rotating assembly. As one of the bearing MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 20 races rotates it causes the rotate as well because the ball are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other. Bearing balls are manufactured to a specific grade, which defines its geometric tolerance. The grades range from 2000 to 3, where the smaller the number the higher the precision. Grades are written "GXXXX", i.e. grade 100 would be "G100". The grades are divided into two categories: semi-precision and precision. Grades 100 and greater are semi-precision balls and lower than that is precision balls. The specification defines three parameters: surface integrity, size, and sphericity. The surface integrity refers to surface smoothness, hardness, and lack of defects, such as flats, pits, soft spots, and cuts. The surface smoothness is measured in two ways surface roughness and waviness. The bearing used in the turbine is 6802.

Figure 3.4 Ball Bearing

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 21 CHAPTER 4 WORKING Adhesion and viscosity are the two properties of any fluid, these two properties work together in the tesla turbine to transfer energy from the fluid to the rotor or vice versa. As the fluid moves past each disk, adhesive forces cause the fluid molecules just above the metal surface to slow down and stick. The molecules just above those at the surface slow down when they collide with the molecules sticking to the surface. These molecules in turn slow down the flow just above them. The farther one moves away from the surface, the fewer the collisions affected by the object surface. At the same time, viscous forces cause the molecules of the fluid to resist separation. This generates a pulling force that is transmitted to the disk, causing the disk to move in the direction of the fluid. The thin layer of fluid that interacts with the disk surface in this way is called the boundary layer, and the interaction of the fluid with the solid surface is called the boundary layer effect. As a result of this effect, the propelling fluid follows a rapidly accelerated spiral path along the disk faces until it reaches a suitable exit with proper use of the analytical results, the rotor efficiency using laminar flow can be very high, even above 95%. The reason why the Tesla turbine rotates with such high rpm can be found in two very basic properties of fluids: adhesion and viscosity. Adhesion is defined as the propensity of dissimilar molecules to get attracted. Viscosity is defined as the resistance developed within a fluid when subjected to flow. These two properties produce a combined effect in the turbine for transferring the energy from the air/water to the rotor or the other way round in the following manner. As the fluid moves over each disk, the force of adhesion slows down the fluid molecules just above the disc and thus, they stick on to the surface. The molecules just above the ones which are glued to the surface slow down when they strike them. This process continues level by level and thus a chain reaction is initiated. The farther the distance from the surface, the smaller the effect of adhesion. But the viscous forces prevent the molecules from separation. This results in a torque being transmitted to the disk, which imparts rotation to the disk in the direction in which the fluid interacts with it. Thus, this thin layer of fluid which imparts torque to the discs by acting on the boundaries of the fluid-disc contact surface is called boundary layer and the net effect is called boundary layer effect. The net results of this whole process in that fluid takes a spiral path from the boundary to the center of the disc, from it exists through the exhaust holes provided, thereby rotating the discs rapidly.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 22 4.1 MECHANISM The Tesla turbine is a bladeless centripetal flow turbine. It is referred to as a bladeless turbine because of its property that fluid impinges on the blade as a same done in the convectional turbine. A Tesla turbine consist of a smooth discs with nozzles applying a moving gas to the edge of the disk by means of viscosity and the adhesion of the surface layer of the gas. As the gas flows and adds energy to the disks, it spirals into the center exhaust since the rotor has no projections, it is very sturdy. Now explaining the detailed mechanism involved in the process of the turbine. Firstly the main objective of the working of the turbine is to rotate the disk connected to the shaft .For this to be done. We need air pressure to be applied in tangential direction with respect to the discs connected to the rotor as well as shaft. The air pressure must be more than 40 Psi. For creating the air pressure, we have applied a mechanism consisting of two air-pumps (used for Exercising) that are fixed on a plyboard which is of 18*18 inch. Set at the center of the plywood. The air is transferred to a cylinder through T-joint connected via non-return valves of 10kg/cm2. The air then compressed at 50psi is sent to the turbine through pneumatic pipe and the flow of the air is controlled by a gate valve. Compressed air is passed to the turbine through the air inlet nozzle at the top of the turbine. The air injected through the nozzle passes through the gaps between the disks creating a boundary layer which results in rotation of the shaft. The shaft then transfer the power to a dynamo generating electric current which is here used to lit the LEDs and also can be used for various purposes.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 23 CHAPTER 5 COMMERCIAL VIABILITY OF THE NEW PROPOSALS 5.1 THE EFFICIENCY FACTOR - Tesla Turbine is more efficient than most of the prime movers which are currently in use commercially. The following chart shows the average efficiency of a bladed turbine (Pelton turbine, Kaplan turbine, Francis turbine etc.), a gas piston, a diesel engine, a fuel cell and a Tesla Turbine. Thus, if the Tesla turbine is adopted on a commercial basis, the efficiency level of the process, be it generating current or pumping water, will see a marked improvement when compared to the current scenario. By adopting the newly proposed fluid and rotor design, this efficiency is expected to increase even further, thereby pushing the cause of the Tesla Turbine even further. 5.2 THE COST FACTOR- The following is the comparison between the estimated cost of the new proposed Tesla turbine and the other machines mentioned earlier. Here, it can be seen that the expected cost of the proposed Tesla Turbine is not too high when compared to its peers. This expected cost has been calculated after taking into account the cost of the laminated composite rotors. The costs of the other machines are their average market costs. Thus, the Tesla turbine provides an alternative solution to todays energy problems, at a cost which is much lower than the other commercially wide-spread machines. 5.3 THE SUSTAINABILITY FACTOR - In todays world which emphasizes green technologies, the Tesla turbine is an ideal candidate for future power generation, water pumping etc. The fact that the properties of adhesion and viscosity combine together to generate much more power than the power consumed by the compressor which is used to provide the compressed air to the Tesla Turbine rotor is of much importance. Even the power consumed by the air heater to heat the air to 80C will be compensated in the former of a much higher torque generation by the proposed modified Tesla turbine. Especially in areas such as hydraulic power applications, such a high torque can play a very significant role. 5.4 CALCULATING THE IDEAL NUMBER OF DISCS - To estimate the total number of disks for the turbine, assume that at a given internal circumference of the disk, the flow Reynolds number is less than 2300. Taking the number of disc as according to our need. Then assuming it to be a number of 8 and proceeding further operations. 5.5 EFFICIENCY AND CALCULATION - Tesla's time, the efficiency of conventional turbines was low because the aerodynamic theory needed for effective blade design did not exist and the low quality of materials available to construct those blades put severe limitations on operating speeds and temperatures. The efficiency of a conventional turbine is related to the pressure difference between the intake and the MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 24 exhaust. To achieve a higher pressure difference very hot fluids such as superheated steam are used which is why the availability of higher temperature materials allow higher efficiencies. If the turbine uses a gas which is liquid at room temperature then you can use a condenser after the exhaust to increase the pressure difference.

Tesla's design sidestepped the key drawbacks of the bladed turbine. It does suffer from other problems such as shear losses and flow restrictions. Some of Tesla turbine's advantages lie in relatively low flow rate applications or when small applications are called for. The disks need to be as thin as possible at the edges in order not to introduce turbulence as the fluid leaves the disks. This translates to needing to increase the number of disks as the flow rate increases. Maximum efficiency comes in this system when the inter-disk spacing approximates the thickness of the boundary layer, and since boundary layer thickness is dependent on viscosity and pressure, the claim that a single design can be used efficiently for a variety of fuels and fluids is incorrect. A Tesla turbine differs from a conventional turbine only in the mechanism used for transferring energy to the shaft. Various analyses demonstrate the flow rate between the disks must be kept relatively low to maintain efficiency. Reportedly, the efficiency of the Tesla turbine drops with increased load. Under light load, the spiral taken by the fluid moving from the intake to the exhaust is a tight spiral, undergoing many rotations. Under load, the number of rotations drops and the spiral becomes progressively shorter. This will increase the shear losses and also reduce the efficiency because the gas is in contact with the discs for less distance. Efficiency is a function of power output. A light load makes for high efficiency and a heavy load, which increases the slip in the turbine and lowers the efficiency, though this is not exclusive to Tesla turbines. The turbine effeciency of the gas Tesla turbine is estimated to be above 60, reaching a maximum of 95 percent. Keep in mind that turbine efficiency is different from the cycle efficiency of the engine using the turbine. Axial turbines which operate today in steam plants or jet engines have efficiencies of about 60 - 70% (Siemens Turbines Data). This is different from the cycle efficiencies of the plant or engine which are between approximately 25% and 42%, and are limited by any to fall below the turbine efficiency. Tesla claimed that a steam version of his device would achieve around 95 percent efficiency. Actual tests of a Tesla Steam Turbine at the Westinghouse works showed a steam rate of 38 pounds per horsepower hour, corresponding to a turbine efficiency in the range of 20%, while contemporary steam turbines could often achieve turbine efficiencies of well over 50%. The methods and apparatus for the propulsion of fluids and thermodynamic transformation of energy were disclosed in various patents. The thermodynamic efficiency is a measure of how well it performs compared to an isentropic case. It is the ratio of the ideal to the actual work input/output. This can be taken to be the ratio of the ideal change in enthalpy to the real enthalpy for the same change in pressure. MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 25 In the 1950s, Warren Rice attempted to re-create Tesla's experiments, but he did not perform these early tests on a pump built strictly in line with the Tesla's patented design (it, among other things, was not a Tesla multiple staged turbine nor did it possess Tesla's nozzle). Rice's experimental single stage system's working fluid was air. Rice's test turbines, as published in early reports, produced an overall measured efficiency of 36% to 41% for a single stage. Higher percentages would be expected if designed as originally proposed by Tesla. In his final work with the Tesla turbine and published just prior to his retirement, Rice conducted a bulk-parameter analysis of model laminar flow in multiple disk turbines. A very high claim for rotor efficiency (as opposed to overall device efficiency) for this design was published in 1991 entitled "Tesla Turbo machinery". This paper states: "With proper use of the analytical results, the rotor efficiency using laminar flow can be very high, even above 95%. However, in order to attain high rotor efficiency, the flow rate number must be made small which means high rotor efficiency is achieved at the expense of using a large number of disks and hence a physically larger rotor." Modern multiple stage bladed turbines typically reach 60% - 70% efficiency, while large steam turbines often show turbine efficiency of over 90% in practice. Volute rotor matched Tesla-type machines of reasonable size with common fluids (steam, gas, and water) would also be expected to show efficiencies in the vicinity of 60% - 70% and possibly higher.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 26 CHAPTER 6 UTILITIES Tesla Turbine is more efficient than most of the prime movers which are currently in use commercially. The following chart shows the average efficiency of a bladed turbine (Pelton turbine, Kaplan turbine, Francis turbine etc.), a gas piston, a diesel engine, a fuel cell and a Tesla Turbine. Thus, if the Tesla turbine is adopted on a commercial basis, the efficiency level of the process, be it generating current or pumping water, will see a marked improvement when compared to the current scenario. By adopting the newly proposed fluid and rotor design, this efficiency is expected to increase even further, thereby pushing the cause of the Tesla Turbine even further. In todays world which emphasizes green technologies, the Tesla turbine is an ideal candidate for future power generation, water pumping etc. The fact that the properties of adhesion and viscosity combine together to generate much more power than the power consumed by the compressor which is used to provide the compressed air to the Tesla Turbine rotor is of much importance. Even the power consumed by the air heater to heat the air to 80C will be compensated in the former of a much higher torque generation by the proposed modified Tesla turbine. Especially in areas such as hydraulic power applications, such a high torque can play a very significant role.

6.1 ADVANTAGES Simple in construction. Corrosion and cavitation is less. Pollution free. Low cost to produce and maintain. This type of equipment can be operated at a wide range of working medium parameters without any danger and malfunction. It is not so sensitive to a partially polluted working medium, since the fluid flow is parallel to disks, so it can be operated with saturated steam. This turbine can be adjusted to different circumstances by applying a few cross section has to be adjusted to the actual demand which is an interchangeable part of the equipment It is a bladeless turbine working smoothly by spinning of central disc by friction from a gas or fluid. Since the turbine itself has no drawback, it is extremely stable. MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 27 6.2 DISADVANTAGES Low rotor torque. Often not suitable for a direct replacement for conventional turbines and pumps, without changes to the machinery it is interacting with. Proof of its efficiency compared to conventional turbines is still questionable and needs more research. It has remained underdeveloped and hence design improvements are still being made. Need more changes to the initial design to reach theoretical values.

6.3 APPLICATIONS Tesla turbine has not seen widespread commercial use since its invention. The Tesla pump, however, has been commercially available since 1982 and is used to pump fluids that are abrasive, viscous, contain solids, shear sensitive or otherwise difficult to handle with other pumps. Applications of the Tesla turbine as a multiple-disk centrifugal blood pump have yielded promising results. Biomedical engineering research on such applications has been continued into the 21st century.

MAJOR PROJECT REPORT ON TESLA TURBINE SHAHEED BHAGAT SINGH STATE TECHNICAL CAMPUS 28 CHAPTER 7 CONCLUSION AND SCOPE FOR FUTURE WORK 7.1 CONCLUSION In this project, an effort has been made to push the case of the commercialization of the Tesla Turbine. Tesla turbine should be considered in applications in which conventional machines are inadequate. This includes applications for small shaft power, or the use of very viscous fluid or non-Newtonian fluids. Multiple-disk turbine can operate with abrasive two-phase flow mixtures with less erosion of material from the rotor. For that reason, they should be further investigated for applications to produce power from geothermal steam and particle-laden industrial gas flows. There may also be unique applications possible using ceramic disks. There is considerable evidence that multiple-disk turbine can be quieter in operation than is conventional machinery and that the noise produced is more nearly white noise without a prevailing sound signature. Multiple-disk pumps are well known to resist cavitation. It is the only type of turbine that can be easily constructed in a relatively primitive machine shop. Although Tesla himself described that the Tesla Turbine was his greatest invention, it has not found widespread acceptance. It is expected that by analyzing the reasons for that and suggesting improvements like a new working fluid and a new rotor material, a small step forward to commercialize this turbine has been made. The higher torque generation of such a modified Tesla Turbine is expected to revive its fortunes in the commercial market.

7.2 SCOPE FOR FUTURE WORK It has been found that the efficiency of the rotor can be very high, at least equal to that achieved by conventional rotors. But it has proved very difficult to achieve efficient nozzles in the case of turbines. For pumps and compressors, efficient diffusion after the rotor has proven difficult to achieve. As a result, only modest machine efficiencies have been demonstrated. The ability of the laminated composite material, with which the rotor is to be constructed, to absorb high stress concentration levels, both thermal and structural, will prove to be beneficial.